Iran threatened to scupper a deal to increase crude supplies among major producers on Thursday, with the country’s oil minister indicating a rift was deepening with Saudi Arabia and Russia.

Bijan Zanganeh said the discussions were “not good”, as he left a technical meeting of delegates early on Thursday evening in Vienna, suggesting Opec remains far from agreement on whether to raise production at its formal gathering of ministers on Friday.

Saudi Arabia and Russia are pushing to increase output to ease a rally in prices that recently hit $80 a barrel, up 50 per cent in 12 months. It has been stoked, in part, by the US decision to withdraw from the nuclear deal with Iran and reimpose sanctions on its oil industry. Fellow Opec member Venezuela has also seen its output collapse due to a political crisis in the country.